Portable Terminal Device and Key Arrangement Control Method

1. A method comprising: determining, by a portable terminal device, whether a user has caused the portable terminal device having a display screen and a touchscreen separate from the display screen on which a keypad is displayed to enter a screen change mode in which a position and a size of the keypad on the touchscreen is changed; and in response to determining that the user has caused the portable terminal device to enter the screen change mode, performing: retrieving, by the portable terminal device, hold data, the hold data comprising an extent to which the user is in contact with a first side of the portable terminal device and an extent to which the user is in contact with a second side of the portable terminal device opposite the first side; determining, by the portable terminal device, whether the hold data indicates the user is in contact with one or more of the first side and the second side; in response to determining that the hold data indicates the user is not in contact with the one or more of the first side and the second side, displaying, by the portable terminal device, the keypad in full size such that the keypad takes up the touchscreen in entirety; and in response to determining that the hold data indicates that the user is in contact with the one or more of the first side and the second side, performing: determining, by the portable terminal device, whether the hold data indicates the user is holding the portable terminal device in a right hand of the user; in response to determining that the hold data indicates the user is holding the portable terminal device in the right hand, displaying the keypad on the touchscreen such that the keypad is oriented towards a right-bottom corner of the touchscreen, and such that the size of the keyboard is according to the extent to which the user is in contact with the first side and the extent to which the user is in contact with the second side, the size of the keypad being such that the keypad does not take up the touchscreen in entirety, the size of the keypad being such that a thumb of the right hand of the user is able to reach an upper-left corner of the keypad due to the size of the keypad being reduced in size, the upper-left corner being a right angle, where the size of the keypad is larger where the user is more in contact with the one or more of the first side and the second side and the size of the keypad is smaller compared to the larger size where the user is less in contact with the one or more of the first side and the second side; and in response to determining that the hold indicates the user is not holding the portable terminal device in the right hand, concluding that the user is holding the portable terminal device in a left hand of the user, displaying the keypad on the touchscreen such that the keypad is oriented towards a left-bottom corner of the touchscreen, and such that the size of the keyboard is according to the extent to which the user is in contact with the first side and the extent to which the user is in contact with the second side, the size of the keypad being such that the keypad does not take up the touchscreen in entirety, the size of the keypad being such that a thumb of the left hand of the user is able to reach an upper-right corner of the keypad due to the size of the keypad being reduced in size, the upper-right corner being a right angle, where the size of the keypad is larger where the user is more in contact with the one or more of the first side and the second side and such that the size of the keypad is smaller compared to the larger size where the user is less in contact with the one or more of the first side and the second side.

2. A portable terminal device comprising: a housing having a top part and a bottom part; a display screen within the top part of the housing; a touchscreen within the bottom part of the housing and on which a keypad is displayed; a hardware detection mechanism at a first side and at a second side of the bottom part of the housing to detect hold data comprising an extent to which a user is in contact with the first side and an extent to which the user is in contact with the second side; and a display control mechanism to, responsive to the user invoking a screen change mode in which a position and a size of the keypad on the touchscreen is changed: determine whether the hold data indicates the user is in contact with one or more of the first side and the second side; in response to determining that the hold data indicates the user is not in contact with the one or more of the first side and the second side, display the keypad in full size such that the keypad takes up the touchscreen in entirety; and in response to determining that the hold data indicates that the user is in contact with the one or more of the first side and the second side: determine whether the hold data indicates the user is holding the portable terminal device in a right hand of the user; in response to determining that the hold data indicates the user is holding the portable terminal device in the right hand, display the keypad on the touchscreen such that the keypad is oriented towards a right-bottom corner of the touchscreen, and such that the keypad has a size according to the extent to which the user is in contact with the first side and the extent to which the user is in contact with the second side, the size of the keypad being such that the keypad does not take up the touchscreen in entirety, the size of the keypad being such that a thumb of the right hand of the user is able to reach an upper-left corner of the keypad due to the size of the keypad being reduced in size, the upper-left corner being a right angle, where the size of the keypad is larger where the user is more in contact with the one or more of the first side and the second side and the size of the keypad is smaller compared to the larger size where the user is less in contact with the one or more of the first side and the second side; and in response to determining that the hold indicates the user is not holding the portable terminal device in the right hand, conclude that the user is holding the portable terminal device in a left hand of the user, and display the keypad on the touchscreen such that the keypad is oriented towards a left-bottom corner of the touchscreen, and such that the keypad has the size according to the extent to which the user is in contact with the first side and the extent to which the user is in contact with the second side, the size of the keypad being such that the keypad does not take up the touchscreen in entirety, the size of the keypad being such that a thumb of the left hand of the user is able to reach an upper-right corner of the keypad due to the size of the keypad being reduced in size, the upper-right corner being a right angle, where the size of the keypad is larger where the user is more in contact with the one or more of the first side and the second side and such that the size of the keypad is smaller compared to the larger size where the user is less in contact with the one or more of the first side and the second side.